build: add nix flake for hermetic dev environments

.gitignore

@@ -216,6 +216,7 @@ node_modules
 .next
 next-env.d.ts
 .env
+.envrc
 out
 
 # docker test
@@ -226,3 +227,5 @@ out
 
 # integration testing coverage
 coverage-test-unit-cover.txt
+
+.direnv/

README.md

@@ -53,6 +53,8 @@ If you want to help contribute to the framework, check out the [Framework Specs]
 
 ## Build & Test
 
+### Standard Development Environment
+
 [Golang 1.20+](https://go.dev/doc/install) and [Foundry](https://book.getfoundry.sh/getting-started/installation) are required for Polaris.
 
 1. Install [go 1.21+ from the official site](https://go.dev/dl/) or the method of your choice. Ensure that your `GOPATH` and `GOBIN` environment variables are properly set up by using the following commands:
@@ -97,6 +99,34 @@ If you want to help contribute to the framework, check out the [Framework Specs]
  make start
  ```
 
+### Nix Flakes Development Environment
+
+Polaris also supports reproducible development environments using [Nix](https://nixos.org/) with [Flakes](https://nixos.wiki/wiki/Flakes).
+
+1. Install [Nix](https://github.com/DeterminateSystems/nix-installer). We recommend the Determinate Systems installer to automatically configure your system with Flakes turned on.
+
+2. Clone, Setup and Test:
+
+ ```sh
+ cd $HOME
+ git clone https://github.com/berachain/polaris
+ cd polaris
+ git checkout main
+ nix develop
+ make test-unit
+ ```
+
+3. Start a local development network:
+
+ ```sh
+ make start
+ ```
+
+Note: If you would prefer to automatically load this environment everytime you enter the Polaris directory, you can use `direnv`:
+
+- Create a `.envrc` file with the line `use flake`
+- Run `direnv allow`
+
 ## 🚧 WARNING: UNDER CONSTRUCTION 🚧
 
 This project is work in progress and subject to frequent changes as we are still working on wiring up the final system.

flake.nix

@@ -0,0 +1,35 @@
+{
+ description = "An EVM framework for Cosmos";
+
+ inputs = {
+ nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+ flake-utils.url = "github:numtide/flake-utils";
+ foundry.url = "github:shazow/foundry.nix/monthly";
+ };
+
+
+ outputs = { self, nixpkgs, flake-utils, foundry, ... }:
+ flake-utils.lib.eachDefaultSystem (system:
+ let
+ pkgs = import nixpkgs {
+ inherit system;
+ overlays = [ foundry.overlay ];
+ };
+ in {
+ devShell = with pkgs; mkShell {
+ name = "polaris-dev";
+ nativeBuildInputs = [
+ gnumake
+ go
+ jq
+ foundry-bin
+ ];
+
+
+ shellHook = ''
+ export PS1="[dev] $PS1"
+ '';
+ };
+ }
+ );
+}